This new poinsettia cultivar, `721`, originated as an induced self-branching sport of a seedling known as "M-02" (not patented) in my greenhouse in Encinitas, Calif. It was selected because of its bright red flower bracts, dark green foliage, self branching characteristics, and uniform growth habit; traits that distinguish it from other poinsettia cultivars, and seem to make it a desirable plant for commercial greenhouse production. After selection, `721` was vegetatively reproduced from stem cuttings for test purposes in Encinitas, Calif. "M-02" is a proprietary plant and there are no specimens in the public domain. Poinsettia "M-02" is not self-branching in that no axillary branches develop as long as the apical bud is not removed (pinched). `721` is self-branching in that during development axillary branches elongate without removal of the apical bud. If under short day conditions, the axillary branches will develop inflorescences. Poinsettia `721` most closely resembles poinsettia `140` (U.S. Plant Pat. No. 7,874), but differs in these aspects: `721` has a more uniform growth habit, more cyathia, smoother flower bracts and flowers later than `140` under the same cultural conditions. By subjecting clones of this plant to successive generations of vegetative propagation, it was demonstrated that the distinctive characteristics of `721` held true from generation to generation.